Present computer data networks, such as the Internet, besides computer data services, also provide telecommunications services, such as traditional telephony. The integration of computer and telephony services has led to peripheral equipment offering computer and telecommunications services.
For telecommunications services, such as telephony, facsimily and other data transmissions, special networks like the Public Switched Telephone Network (PSTN) and the Integrated Services Digital Network (ISDN) are available. Modern PSTN/ISDN Intelligent Networks (IN) have an architecture comprising computer controlled Service Switching Point (SSP) equipment, providing call management and switching functions, Service Control Point (SCP) equipment, containing service profiles of subscribers of the network, and Service Data Point (SDP) data base equipment.
The subscribers of an IN telecommunications system, may roam to different sites maintaining their telecommunications services.
With the increased opportunities of data networks providing telecommunications service and data equipment offering special functions, such as broadcast message transfer, multidialing etc., users of a data network require easy access to both the telecommunications services of the data network and IN telecommunications systems for completing calls, among others telephone calls. Further, subscribers to an IN telecommunication system may have a need for roaming to a data network while maintaining their services available from the telecommunications system.
International patent application WO 96/38018 discloses a method of and system for setting up a speech connection between a data network and an IN telecommunications network, which networks are linked by a so-called gateway. A gateway provides an interface to the data network, operating under a data network protocol, and the telecommunications network, operating under a telecommunications network protocol.
The data network is arranged to support telecommunications service in the data network and between the data network and the telecommunications network. Information between the networks is exchanged via the gateway.
Following the method disclosed in WO 96/38018 a communication link is established between the data network and the IN telecommunications network by transferring, to SCP equipment of the IN telecommunications network, among others, the data network address of the user for recording in the SDP equipment. The information stored is used for routing calls between the different networks to and from the user.
With the increase of calls between networks, for privacy and maintenance purposes, operators target at network integrity, that is preventing as much as possible transfer and storage of alien information not applicable to operations of the particular network. In the method disclosed by WO 96/38018 such alien information is the data network address stored in the SDP equipment of the IN telecommunications system.
In an article by Patel, A et al., “Introduction to names, addresses and routes in an OSI environment”, Computer Communications, vol. 13, no. 1, January/February 1990, pages 27-36, an addressing scheme within the context of an Open Systems Interconnection (OSI) system is disclosed.
In an OSI environment many entities exist. Entities may range from physical objects (e.g. hosts, gateways, routers, printers), to logical entities (e.g. processes, services, agents, roles).
For assigning human readable names to such entities, an addressing scheme has been disclosed comprising addresses identifying entities to which named objects are bound. This name-to-address mapping is achieved by means of a directory look-up. By introducing addresses, user-friendly names can be applied to the several entities which may exist in an OSI environment.